Ghost should let you run through one wall.

if i ever see a ragnarok righteous glory'd olaf run through a wall at me we're gonna have more than a few fuckin problems

As long as it's not Azir's, maybe.

I would run it on Bard just for even more hilarious gank paths and jukes.

But if ghost could let you run through walls why go flash ghost is on a shorter cooldown still lets you go through walls and you get ms rather than just a short blink.

I want summoner spell diversity, but holy shit that's such a bad idea.

Literally everyone would be using some combination of Flash/Ghost/TP, usually Flash/Ghost.

Now I know this sounds like a radical idea but what if instead of changing the summoner spells riot released champions that got more out of some summoners than others? Best example I can think of this right now is Olaf. He tends to take Ghost because he gets far more out of the move speed being able to run after someone pick up his axes and stick that way than he does a single moment of flash....then again that would mean riot has to stop making hypermobile bursty champs and instead make champs that focus on constant damage and needing to stay on a target a bit longer than it takes to blink...just a thought.